bupropion (byoo-proe-pee-on) Wellbutrin, Wellbutrin SR, Wellbutrin XL, Zyban
CLASSIFICATION(S) Therapeutic: antidepressants, smoking deterrants Pharmacologic: aminoketones
Pregnancy Category B
INDICATIONS
• Treatment of depression (with psychotherapy) • Smoking cessation (Zyban only) • Unlabelled Uses: • Treatment of ADHD in adults (SR only) • To increase sexual desire in women
ACTION
• Decreases neuronal reuptake of dopamine in the CNS • Diminished neuronal uptake of serotonin and norepinephrine (less than tricyclic antidepressants) • Therapeutic Effects: ○ Diminished depression ○ Decreased craving for cigarettes
PHARMACOKINETICS
Absorption: Although well absorbed, rapidly and extensively metabolized by the liver Distribution: Unknown Metabolism and Excretion: Extensively metabolized by the liver. Some conversion to active metabolites Half-life: 14 hr (active metabolites may have longer half-lives)
TIME OF ACTION
antidepressant effect ROUTE ONSET PEAK DURATION PO 1-3 wk unknown unknown
CONTRAINDICATIONS/PRECAUTIONS
Contraindicated in: • Hypersensitivity • History of bulimia, and anorexia nervosa • Concurrent MAO inhibitor or ritonavir therapy Use Cautiously in: • Renal/hepatic impairment (↓ dose recommended) • Recent history of MI • Geri: Geriatric patients (increased risk of drug accumulation; increased sensitivity to effects) • History of suicide attempt • Unstable cardiovascular status • May ↑ risk of suicide attempt/ideation especially during early treatment or dose adjustment; this risk may be greater in adolescents or children • OB: Pregnancy, lactation • Pedi: Children <18 yr (safety not established) Exercise Extreme Caution in: • History of seizures, head trauma or concurrent medications that ↓ seizure threshold (theophylline, antipsychotics, antidepressants, systemic corticosteroids) • Severe hepatic cirrhosis (↓ dose required)
ADVERSE REACTIONS/SIDE EFFECTS*
*CAPITALS indicate life threatening; underlines indicate most frequent.
CNS: SEIZURES, agitation, headache, insomnia, mania, psychoses, GI: dry mouth, nausea, vomiting, change in appetite, weight gain, weight loss, Derm: photosensitivity, Endo: hyperglycemia, hypoglycemia, syndrome of inappropriate ADH secretion, Neuro: tremor,
INTERACTIONS
Drug-Drug: • ↑ risk of adverse reactions when used with amantadine , levodopa or MAO inhibitors (concurrent use of MAO inhibitors is contraindicated) • ↑ risk of seizures with phenothiazines, antidepressants , theophylline , corticosteroids , OTC stimulants/anorectics, or cessation of alcohol or benzodiazepines (avoid or minimize alcohol use) • Blood levels ↑ by ritonavir (avoid concurrent use) • Carbamazepine may ↓ blood levels and effectiveness • Concurrent use with nicotine replacement may cause hypertension • ↑ risk of bleeding with warfarin • Bupropion and one of its metabolites inhibit the CYP 2D6 enzyme system and may ↑ levels and risk of toxicity from antidepressants (SSRIs and tricyclic), some beta blockers , antiarrhythmics , and antipsychotics
ROUTE AND DOSAGE
Depression • PO (Adults ): Immediate-release--100 mg twice daily initially; after 3 days may increase to 100 mg 3 times daily; after at least 4 wk of therapy, may increase up to 450 mg/day in divided doses (not to exceed 150 mg/dose; wait at least 6 hr between doses at the 300 mg/day dose or at least 4 hr between doses at the 450 mg/day dose). Sustained-release--150 mg once daily in the morning; after 3 days, may increase to 150 mg twice daily with at least 8 hr between doses; after at least 4 wk of therapy, may increase to a maximum daily dose of 400 mg given as 200 mg twice daily. Extended-release--150 mg once daily in the morning, may be increased after 4 days to 300 mg once daily; some patients may require up to 450 mg/day as a single daily dose
Smoking cessation • PO (Adults ): Zyban--150 mg once daily for 3 days, then 150 mg twice daily for 7-12 wk (doses should be at least 8 hr apart)
AVAILABILITY • Tablets: 75 mg, 100 mg • Cost: 75 mg $84.10/100, 100 mg $112.19/100 • Sustained-release tablets: 100 mg, 150 mg, 200 mg • Cost: 100 mg $94.27/60, 150 mg $101.94/60 • Extended-release tablets: 150 mg, 300 mg • Cost: 150 mg $91.63/30, 300 mg $121.03/30
NURSING IMPLICATIONS
ASSESSMENT
• Monitor mood changes. Inform physician or other health care professional if patient demonstrates significant increase in anxiety, nervousness, or insomnia • Assess for suicidal tendencies, especially during early therapy. Restrict amount of drug available to patient • Lab Test Considerations: Monitor hepatic and renal function closely in patients with kidney or liver impairment to prevent ↑ serum and tissue bupropion concentrations
POTENTIAL NURSING DIAGNOSES
• Ineffective coping (Indications).
IMPLEMENTATION
• Do not confuse bupropion with buspirone. Do not confuse Zyban (bupropion) with Zagam (Sparfloxacin). Do not administer bupropion (Wellbutrin) with Zyban, contain same ingredients ○ Administer doses in equally spaced time increments during day to minimize the risk of seizures. Risk of seizures increases four fold in doses greater than 450 mg per day ○ May be initially administered concurrently with sedatives to minimize agitation. This is not usually required after the 1st wk of therapy ○ Insomnia may be decreased by avoiding bedtime doses. May require treatment during 1st wk of therapy ○ May be administered with food to lessen GI irritation ○ Nicotine patches, gum, inhalers, and spray may be used concurrently with bupropion • PO: Sustained-release (SR or XL) tablets should be swallowed whole; do not break, crush, or chew
PATIENT/FAMILY TEACHING
• Instruct patient to take bupropion as directed. Take missed doses as soon as possible and space day's remaining doses evenly at not less than 4-hr intervals. Missed doses for smoking cessation should be omitted. Do not double doses or take more than prescribed. May require 4 wk or longer for full effects. Do not discontinue without consulting health care professional. May require gradual reduction before discontinuation • Bupropion may impair judgment or motor and cognitive skills. Caution patient to avoid driving and other activities requiring alertness until response to medication is known • Advise patient to avoid alcohol during therapy and to consult with health care professional before taking other medications with bupropion • Inform patient that frequent mouth rinses, good oral hygiene, and sugarless gum or candy may minimize dry mouth. If dry mouth persists for more than 2 wk, consult health care professional regarding use of saliva substitute • Advise patient to notify health care professional if rash or other troublesome side effects occur • Inform patient that unused shell of XL tablets may appear in stool; this is normal • Advise patient to use sunscreen and protective clothing to prevent photosensitivity reactions • Instruct female patients to inform health care professional if pregnancy is planned or suspected • Advise patient to notify health care professional of medication regimen before treatment or surgery • Emphasize the importance of follow-up exams to monitor progress. Encourage patient participation in psychotherapy • Smoking Cessation: Smoking should be stopped during the 2nd week of therapy to allow for the onset of bupropion and to maximize the chances of quitting
EVALUATION/DESIRED OUTCOMES
• Increased sense of well-being ○ Renewed interest in surroundings. Acute episodes of depression may require several months of treatment • Cessation of smoking
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